stream.c

uclinux 下的vlc播放器源代码

            }
        }

        p_sys->block.i_offset = i_pos - p_sys->i_pos;
        p_sys->i_pos = i_pos;

        /* TODO read data */
        return VLC_SUCCESS;
    }

    return VLC_EGENERIC;
}

static int AStreamRefillBlock( stream_t *s )
{
    stream_sys_t *p_sys = s->p_sys;
    int64_t      i_start, i_stop;
    block_t      *b;

    /* Release data */
    while( p_sys->block.i_size >= STREAM_CACHE_SIZE &&
           p_sys->block.p_first != p_sys->block.p_current )
    {
        block_t *b = p_sys->block.p_first;

        p_sys->block.i_start += b->i_buffer;
        p_sys->block.i_size  -= b->i_buffer;
        p_sys->block.p_first  = b->p_next;

        block_Release( b );
    }
    if( p_sys->block.i_size >= STREAM_CACHE_SIZE &&
        p_sys->block.p_current == p_sys->block.p_first &&
        p_sys->block.p_current->p_next )    /* At least 2 packets */
    {
        /* Enough data, don't read more */
        return VLC_SUCCESS;
    }

    /* Now read a new block */
    i_start = mdate();
    for( ;; )
    {
        vlc_bool_t b_eof;

        if( s->b_die ) return VLC_EGENERIC;


        /* Fetch a block */
        if( ( b = AReadBlock( s, &b_eof ) ) ) break;

        if( b_eof ) return VLC_EGENERIC;

        msleep( STREAM_DATA_WAIT );
    }

    while( b )
    {
        i_stop = mdate();

        /* Append the block */
        p_sys->block.i_size += b->i_buffer;
        *p_sys->block.pp_last = b;
        p_sys->block.pp_last = &b->p_next;

        /* Fix p_current */
        if( p_sys->block.p_current == NULL )
            p_sys->block.p_current = b;

        /* Update stat */
        p_sys->stat.i_bytes += b->i_buffer;
        p_sys->stat.i_read_time += i_stop - i_start;
        p_sys->stat.i_read_count++;

        b = b->p_next;
        i_start = mdate();
    }
    return VLC_SUCCESS;
}


/****************************************************************************
 * Method 2:
 ****************************************************************************/
static int AStreamRefillStream( stream_t *s );

static int AStreamReadStream( stream_t *s, void *p_read, int i_read )
{
    stream_sys_t *p_sys = s->p_sys;
    stream_track_t *tk = &p_sys->stream.tk[p_sys->stream.i_tk];

    uint8_t *p_data = (uint8_t *)p_read;
    int      i_data = 0;

    if( tk->i_start >= tk->i_end ) return 0; /* EOF */

    if( p_read == NULL )
    {
        /* seek within this stream if possible, else use plain old read and discard */
        stream_sys_t *p_sys = s->p_sys;
        access_t     *p_access = p_sys->p_access;
        vlc_bool_t   b_aseek;
        access2_Control( p_access, ACCESS_CAN_SEEK, &b_aseek );
        if( b_aseek )
            return AStreamSeekStream( s, p_sys->i_pos + i_read ) ? 0 : i_read;
    }

#ifdef STREAM_DEBUG
    msg_Dbg( s, "AStreamReadStream: %d pos="I64Fd" tk=%d start="I64Fd
             " offset=%d end="I64Fd,
             i_read, p_sys->i_pos, p_sys->stream.i_tk,
             tk->i_start, p_sys->stream.i_offset, tk->i_end );
#endif

    while( i_data < i_read )
    {
        int i_off = (tk->i_start + p_sys->stream.i_offset) %
                    STREAM_CACHE_TRACK_SIZE;
        int i_current =
            __MIN( tk->i_end - tk->i_start - p_sys->stream.i_offset,
                   STREAM_CACHE_TRACK_SIZE - i_off );
        int i_copy = __MIN( i_current, i_read - i_data );

        if( i_copy <= 0 ) break; /* EOF */

        /* Copy data */
        /* msg_Dbg( s, "AStreamReadStream: copy %d", i_copy ); */
        if( p_data )
        {
            memcpy( p_data, &tk->p_buffer[i_off], i_copy );
            p_data += i_copy;
        }
        i_data += i_copy;
        p_sys->stream.i_offset += i_copy;

        /* Update pos now */
        p_sys->i_pos += i_copy;

        /* */
        p_sys->stream.i_used += i_copy;
        if( tk->i_start + p_sys->stream.i_offset >= tk->i_end ||
            p_sys->stream.i_used >= p_sys->stream.i_read_size )
        {
            if( AStreamRefillStream( s ) )
            {
                /* EOF */
                if( tk->i_start >= tk->i_end ) break;
            }
        }
    }

    return i_data;
}

static int AStreamPeekStream( stream_t *s, uint8_t **pp_peek, int i_read )
{
    stream_sys_t *p_sys = s->p_sys;
    stream_track_t *tk = &p_sys->stream.tk[p_sys->stream.i_tk];
    int64_t i_off;

    if( tk->i_start >= tk->i_end ) return 0; /* EOF */

#ifdef STREAM_DEBUG
    msg_Dbg( s, "AStreamPeekStream: %d pos="I64Fd" tk=%d "
             "start="I64Fd" offset=%d end="I64Fd,
             i_read, p_sys->i_pos, p_sys->stream.i_tk,
             tk->i_start, p_sys->stream.i_offset, tk->i_end );
#endif

    /* Avoid problem, but that should *never* happen */
    if( i_read > STREAM_CACHE_TRACK_SIZE / 2 )
        i_read = STREAM_CACHE_TRACK_SIZE / 2;

    while( tk->i_end - tk->i_start - p_sys->stream.i_offset < i_read )
    {
        if( p_sys->stream.i_used <= 1 )
        {
            /* Be sure we will read something */
            p_sys->stream.i_used += i_read -
                (tk->i_end - tk->i_start - p_sys->stream.i_offset);
        }
        if( AStreamRefillStream( s ) ) break;
    }

    if( tk->i_end - tk->i_start - p_sys->stream.i_offset < i_read )
        i_read = tk->i_end - tk->i_start - p_sys->stream.i_offset;

    /* Now, direct pointer or a copy ? */
    i_off = (tk->i_start + p_sys->stream.i_offset) % STREAM_CACHE_TRACK_SIZE;
    if( i_off + i_read <= STREAM_CACHE_TRACK_SIZE )
    {
        *pp_peek = &tk->p_buffer[i_off];
        return i_read;
    }

    if( p_sys->i_peek < i_read )
    {
        p_sys->p_peek = realloc( p_sys->p_peek, i_read );
        if( !p_sys->p_peek )
        {
            p_sys->i_peek = 0;
            return 0;
        }
        p_sys->i_peek = i_read;
    }

    memcpy( p_sys->p_peek, &tk->p_buffer[i_off],
            STREAM_CACHE_TRACK_SIZE - i_off );
    memcpy( &p_sys->p_peek[STREAM_CACHE_TRACK_SIZE - i_off],
            &tk->p_buffer[0], i_read - (STREAM_CACHE_TRACK_SIZE - i_off) );

    *pp_peek = p_sys->p_peek;
    return i_read;
}

static int AStreamSeekStream( stream_t *s, int64_t i_pos )
{
    stream_sys_t *p_sys = s->p_sys;
    access_t     *p_access = p_sys->p_access;
    vlc_bool_t   b_aseek;
    vlc_bool_t   b_afastseek;
    int i_maxth;
    int i_new;
    int i;

#ifdef STREAM_DEBUG
    msg_Dbg( s, "AStreamSeekStream: to "I64Fd" pos="I64Fd
             " tk=%d start="I64Fd" offset=%d end="I64Fd,
             i_pos, p_sys->i_pos, p_sys->stream.i_tk,
             p_sys->stream.tk[p_sys->stream.i_tk].i_start,
             p_sys->stream.i_offset,
             p_sys->stream.tk[p_sys->stream.i_tk].i_end );
#endif


    /* Seek in our current track ? */
    if( i_pos >= p_sys->stream.tk[p_sys->stream.i_tk].i_start &&
        i_pos < p_sys->stream.tk[p_sys->stream.i_tk].i_end )
    {
        stream_track_t *tk = &p_sys->stream.tk[p_sys->stream.i_tk];
#ifdef STREAM_DEBUG
        msg_Dbg( s, "AStreamSeekStream: current track" );
#endif
        p_sys->i_pos = i_pos;
        p_sys->stream.i_offset = i_pos - tk->i_start;

        /* If there is not enough data left in the track, refill  */
        /* \todo How to get a correct value for
         *    - refilling threshold
         *    - how much to refill
         */
        if( (tk->i_end - tk->i_start ) - p_sys->stream.i_offset <
                                             p_sys->stream.i_read_size )
        {
            if( p_sys->stream.i_used < STREAM_READ_ATONCE / 2  )
            {
                p_sys->stream.i_used = STREAM_READ_ATONCE / 2 ;
                AStreamRefillStream( s );
            }
        }
        return VLC_SUCCESS;
    }

    access2_Control( p_access, ACCESS_CAN_SEEK, &b_aseek );
    if( !b_aseek )
    {
        /* We can't do nothing */
        msg_Dbg( s, "AStreamSeekStream: can't seek" );
        return VLC_EGENERIC;
    }

    /* Date the current track */
    p_sys->stream.tk[p_sys->stream.i_tk].i_date = mdate();

    /* Try to reuse already read data */
    for( i = 0; i < STREAM_CACHE_TRACK; i++ )
    {
        stream_track_t *tk = &p_sys->stream.tk[i];

        if( i_pos >= tk->i_start && i_pos <= tk->i_end )
        {
#ifdef STREAM_DEBUG
            msg_Dbg( s, "AStreamSeekStream: reusing %d start="I64Fd
                     " end="I64Fd, i, tk->i_start, tk->i_end );
#endif

            /* Seek at the end of the buffer */
            if( ASeek( s, tk->i_end ) ) return VLC_EGENERIC;

            /* That's it */
            p_sys->i_pos = i_pos;
            p_sys->stream.i_tk = i;
            p_sys->stream.i_offset = i_pos - tk->i_start;

            if( p_sys->stream.i_used < 1024 )
                p_sys->stream.i_used = 1024;

            if( AStreamRefillStream( s ) && i_pos == tk->i_end )
                return VLC_EGENERIC;

            return VLC_SUCCESS;
        }
    }

    access2_Control( p_access, ACCESS_CAN_SEEK, &b_afastseek );
    /* FIXME compute seek cost (instead of static 'stupid' value) */
    i_maxth = __MIN( p_sys->stream.i_read_size, STREAM_READ_ATONCE / 2 );
    if( !b_afastseek )
        i_maxth *= 3;

    /* FIXME TODO */
#if 0
    /* Search closest segment TODO */
    for( i = 0; i < STREAM_CACHE_TRACK; i++ )
    {
        stream_track_t *tk = &p_sys->stream.tk[i];

        if( i_pos + i_maxth >= tk->i_start )
        {
            msg_Dbg( s, "good segment before current pos, TODO" );
        }
        if( i_pos - i_maxth <= tk->i_end )
        {
            msg_Dbg( s, "good segment after current pos, TODO" );
        }
    }
#endif

    /* Nothing good, seek and choose oldest segment */
    if( ASeek( s, i_pos ) ) return VLC_EGENERIC;
    p_sys->i_pos = i_pos;

    i_new = 0;
    for( i = 1; i < STREAM_CACHE_TRACK; i++ )
    {
        if( p_sys->stream.tk[i].i_date < p_sys->stream.tk[i_new].i_date )
            i_new = i;
    }

    /* Reset the segment */
    p_sys->stream.i_tk     = i_new;
    p_sys->stream.i_offset =  0;
    p_sys->stream.tk[i_new].i_start = i_pos;
    p_sys->stream.tk[i_new].i_end   = i_pos;

    /* Read data */
    if( p_sys->stream.i_used < STREAM_READ_ATONCE / 2 )
        p_sys->stream.i_used = STREAM_READ_ATONCE / 2;

    if( AStreamRefillStream( s ) )
        return VLC_EGENERIC;

    return VLC_SUCCESS;
}

static int AStreamRefillStream( stream_t *s )
{
    stream_sys_t *p_sys = s->p_sys;
    stream_track_t *tk = &p_sys->stream.tk[p_sys->stream.i_tk];

    /* We read but won't increase i_start after initial start + offset */
    int i_toread =
        __MIN( p_sys->stream.i_used, STREAM_CACHE_TRACK_SIZE -
               (tk->i_end - tk->i_start - p_sys->stream.i_offset) );
    vlc_bool_t b_read = VLC_FALSE;
    int64_t i_start, i_stop;

    if( i_toread <= 0 ) return VLC_EGENERIC; /* EOF */

#ifdef STREAM_DEBUG
    msg_Dbg( s, "AStreamRefillStream: used=%d toread=%d",
                 p_sys->stream.i_used, i_toread );
#endif

    i_start = mdate();
    while( i_toread > 0 )
    {
        int i_off = tk->i_end % STREAM_CACHE_TRACK_SIZE;
        int i_read;

        if( s->b_die )
            return VLC_EGENERIC;

        i_read = __MIN( i_toread, STREAM_CACHE_TRACK_SIZE - i_off );
        i_read = AReadStream( s, &tk->p_buffer[i_off], i_read );

        /* msg_Dbg( s, "AStreamRefillStream: read=%d", i_read ); */
        if( i_read <  0 )
        {
            msleep( STREAM_DATA_WAIT );
            continue;
        }
        else if( i_read == 0 )
        {
            if( !b_read ) return VLC_EGENERIC;
            return VLC_SUCCESS;
        }
        b_read = VLC_TRUE;

        /* Update end */
        tk->i_end += i_read;

        /* Windows of STREAM_CACHE_TRACK_SIZE */
        if( tk->i_end - tk->i_start > STREAM_CACHE_TRACK_SIZE )
        {
            int i_invalid = tk->i_end - tk->i_start - STREAM_CACHE_TRACK_SIZE;

            tk->i_start += i_invalid;
            p_sys->stream.i_offset -= i_invalid;
        }

        i_toread -= i_read;
        p_sys->stream.i_used -= i_read;

        p_sys->stat.i_bytes += i_read;
        p_sys->stat.i_read_count++;
    }
    i_stop = mdate();

    p_sys->stat.i_read_time += i_stop - i_start;

    return VLC_SUCCESS;
}

static void AStreamPrebufferStream( stream_t *s )
{
    stream_sys_t *p_sys = s->p_sys;
    access_t     *p_access = p_sys->p_access;

    int64_t i_first = 0;
    int64_t i_start;
    int64_t i_prebuffer = p_sys->b_quick ? STREAM_CACHE_TRACK_SIZE /100 :
        ( (p_access->info.i_title > 1 || p_access->info.i_seekpoint > 1) ?
          STREAM_CACHE_PREBUFFER_SIZE : STREAM_CACHE_TRACK_SIZE / 3 );

    msg_Dbg( s, "pre-buffering..." );
    i_start = mdate();
    for( ;; )
    {
        stream_track_t *tk = &p_sys->stream.tk[p_sys->stream.i_tk];

        int64_t i_date = mdate();
        int i_read;

        if( s->b_die || tk->i_end >= i_prebuffer ||
            (i_first > 0 && i_first + STREAM_CACHE_PREBUFFER_LENGTH < i_date) )
        {